U.S. patent application number 11/154126 was filed with the patent office on 2006-12-21 for airbag tether release mechanism.
Invention is credited to David J. Green, Michael P. Jordan, Brent A. Parks.
Application Number | 20060284404 11/154126 |
Document ID | / |
Family ID | 37570933 |
Filed Date | 2006-12-21 |
United States Patent
Application |
20060284404 |
Kind Code |
A1 |
Green; David J. ; et
al. |
December 21, 2006 |
Airbag tether release mechanism
Abstract
Disclosed are embodiments of an airbag tether release mechanism
for use with airbag inflation systems. In one embodiment, the
mechanism includes an initiator positioned within a housing. The
initiator is configured such that it provides an inherent seal to
prevent the external release of pyrotechnic residues upon
deployment. The device may also include a cutter operatively
connected with the initiator such that deployment of the initiator
actuates the cutter and a tether restraint structure configured to
secure a tether until the tether is released by actuation of the
cutter.
Inventors: |
Green; David J.; (Brigham
City, UT) ; Jordan; Michael P.; (South Weber, UT)
; Parks; Brent A.; (Englewood, CO) |
Correspondence
Address: |
AUTOLIV ASP INC
3350 AIRPORT ROAD
OGDEN
UT
84405
US
|
Family ID: |
37570933 |
Appl. No.: |
11/154126 |
Filed: |
June 16, 2005 |
Current U.S.
Class: |
280/743.2 |
Current CPC
Class: |
B60R 21/231 20130101;
B60R 21/26 20130101; B60R 2021/23386 20130101; B60R 21/2338
20130101; B60R 2021/161 20130101 |
Class at
Publication: |
280/743.2 |
International
Class: |
B60R 21/23 20060101
B60R021/23 |
Claims
1. An airbag tether release mechanism, comprising: a housing; an
initiator positioned within the housing, wherein the initiator is
configured such that it provides an inherent seal to prevent the
external release of pyrotechnic residues upon deployment; a cutter
operatively connected with the initiator such that deployment of
the initiator actuates the cutter; and a tether restraint structure
configured to secure a tether until the tether is released by
actuation of the cutter.
2. The airbag tether release mechanism of claim 1, wherein the
tether restraint structure comprises an opening formed within the
housing.
3. The airbag tether release mechanism of claim 2, wherein the
cutter comprises a piston having an opening formed therein.
4. The airbag tether release mechanism of claim 3, wherein the
cutter is configured such that, prior to deployment of the
initiator, the opening in the housing is at least partially aligned
with the opening in the piston, and wherein, following deployment
of the initiator, the opening in the piston is moved out of
alignment with the opening in the housing.
5. The airbag tether release mechanism of claim 1, wherein the
initiator comprises an output cup having a redrawn end that unrolls
and expands during deployment.
6. The airbag tether release mechanism of claim 1, wherein the
cutter comprises a cutting blade.
7. The airbag tether release mechanism of claim 1, wherein the
tether restraint structure comprises a clip.
8. The airbag tether release mechanism of claim 7, wherein the clip
is configured to snap into a recess formed within the housing.
9. The airbag tether release mechanism of claim 7, wherein the
cutter is configured to sever at least a portion of the clip upon
deployment of the initiator.
10. A method for releasing an airbag tether, comprising:
restraining a tether, wherein the tether is connected to an airbag
cushion; deploying an initiator, wherein the initiator is deployed
without externally releasing pyrotechnic residues; actuating a
cutter, wherein the deployment of the initiator actuates the
cutter; and releasing the tether, wherein the actuation of the
cutter causes the release of the tether.
11. The method of claim 10, wherein the step of releasing the
tether comprises cutting the tether.
12. The method of claim 10, wherein the initiator comprises an
output cup having a redrawn end that unrolls and expands during
deployment.
13. The method of claim 10, wherein the step of releasing the
tether comprises cutting a tether restraint structure.
14. The method of claim 13, wherein the tether restraint structure
comprises a clip.
15. The method of claim 14, wherein the clip comprises at least one
prong.
16. The method of claim 15, wherein the clip comprises at least two
prongs.
17. The method of claim 10, wherein the cutter comprises a piston
having an opening formed therein.
18. The method of claim 17, wherein, prior to the actuation step,
the tether extends through the opening in the piston.
19. The method of claim 18, wherein the actuation of the piston
causes the opening in the piston to be at least partially
misaligned with another opening.
20. The method of claim 10, wherein the cutter comprises a cutting
blade.
21. The method of claim 10, further comprising altering the status
of a vent opening in response to the deployment of the
initiator.
22. The method of claim 21, wherein altering the status of the vent
opening comprises opening the vent opening.
23. The method of claim 21, wherein altering the status of the vent
opening comprises closing the vent opening.
24. The method of claim 21, wherein a connecting rod is connected
with the cutter, and wherein the connecting rod is used to alter
the status of the vent opening.
25. The method of claim 24, wherein a vent door is connected with
the connecting rod.
26. An airbag tether release mechanism, comprising: a housing;
restraining means for restraining an airbag tether; an initiator
positioned within the housing, wherein the initiator is configured
such that it provides an inherent seal to prevent the external
release of pyrotechnic residues upon deployment; and releasing
means for releasing the tether from the restraining means, wherein
the releasing means is actuated by the initiator.
27. The airbag tether release mechanism of claim 26, wherein the
releasing means comprises a cutter.
28. The airbag tether release mechanism of claim 27, wherein the
cutter comprises a cutting blade.
29. The airbag tether release mechanism of claim 27, wherein the
cutter is configured to cut through the tether upon deployment of
the initiator.
30. The airbag tether release mechanism of claim 27, wherein the
cutter is configured to cut through the restraining means upon
deployment of the initiator.
31. The airbag tether release mechanism of claim 26, wherein the
restraining means comprises an opening in the housing.
32. The airbag tether release mechanism of claim 26, wherein the
restraining means comprises a clip.
33. The airbag tether release mechanism of claim 32, wherein the
clip is configured to snap into a recess formed within the
housing.
34. The airbag tether release mechanism of claim 26, wherein the
initiator comprises an output cup having a redrawn end that unrolls
and expands during deployment.
35. An airbag tether release mechanism, comprising: a housing; an
initiator positioned within the housing, wherein the initiator is
configured such that it provides an inherent seal to prevent the
external release of pyrotechnic residues upon deployment; a piston
operatively connected with the initiator such that deployment of
the initiator actuates the piston; a tether restraint structure
configured to secure a tether until the tether is released by
actuation of the piston; and a vent actuator configured to alter
the status of a vent opening in response to the deployment of the
initiator.
36. The airbag tether release mechanism of claim 35, wherein the
vent actuator comprises a connecting rod connected with the
piston.
37. The airbag tether release mechanism of claim 36, wherein the
vent actuator further comprises a vent door connected with the
connecting rod.
38. The airbag tether release mechanism of claim 36, further
comprising a pin structure, wherein the pin structure is used to
prevent the piston from exiting the housing, and wherein the
connecting rod passes by the pin structure and exits the
housing.
39. The airbag tether release mechanism of claim 38, wherein the
pin structure comprises a split spring pin.
40. The airbag tether release mechanism of claim 35, wherein the
vent actuator is configured to alter the status of the vent opening
by opening the vent opening.
41. The airbag tether release mechanism of claim 35, wherein the
vent actuator is configured to alter the status of the vent opening
by closing the vent opening.
42. The airbag tether release mechanism of claim 35, wherein the
initiator comprises an output cup having a redrawn end that unrolls
and expands during deployment.
43. The airbag tether release mechanism of claim 35, wherein the
piston comprises a cutter.
Description
TECHNICAL FIELD
[0001] The present invention relates generally to the field of
automotive protective systems. More specifically, the present
invention relates to a release mechanism for tethers connected with
airbag cushions.
BRIEF DESCRIPTION OF THE DRAWINGS
[0002] Understanding that drawings depict only typical embodiments
of the invention and are not therefore to be considered to be
limiting of its scope, the invention will be described and
explained with additional specificity and detail through the use of
the accompanying drawings in which:
[0003] FIG. 1 is a perspective view of one embodiment of an airbag
tether release mechanism.
[0004] FIG. 2A is a cross-sectional view of the embodiment depicted
in FIG. 1.
[0005] FIG. 2B is a cross-sectional view of the embodiment depicted
in FIGS. 1 and 2A shown after the cutter has cut through and
released the tether.
[0006] FIG. 3A is a perspective view of a second embodiment of an
airbag tether release mechanism.
[0007] FIG. 3B is a perspective view of the embodiment shown in
FIG. 3A after the opening in the piston has been partially
misaligned with the opening in the housing.
[0008] FIG. 3C is a perspective view of the embodiment shown in
FIGS. 3A and 3B after the opening in the piston has been fully
misaligned with the opening in the housing.
[0009] FIG. 4A is a perspective view of a third embodiment of an
airbag tether release mechanism.
[0010] FIG. 4B is a perspective view of the embodiment shown in
FIG. 4A after the cutter has cut through a clip to release the
tether.
[0011] FIG. 5 is a cross-sectional view of a redrawn initiator
suitable for use with embodiments of the disclosed invention.
[0012] FIG. 6A is a perspective view of another embodiment of an
airbag tether release mechanism.
[0013] FIG. 6B is a top plan view of the embodiment depicted in
FIG. 6A.
[0014] FIG. 6C is a side elevation view of the embodiment depicted
in FIG. 6A and FIG. 6B.
[0015] FIG. 7A is a cross-sectional view taken along line 7A-7A in
FIG. 6A prior to deployment of the initiator.
[0016] FIG. 7B is a cross-sectional view like that of FIG. 7A but
taken after deployment of the initiator.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0017] Described below are embodiments of an airbag tether release
mechanism for use with airbag inflation systems. In one embodiment,
the mechanism includes an initiator positioned within a housing.
The initiator is configured such that it provides an inherent seal
to prevent the external release of pyrotechnic residues upon
deployment. The device may include a cutter operatively connected
with the initiator such that deployment of the initiator actuates
the cutter and a tether restraint structure configured to secure a
tether until the tether is released by actuation of the cutter.
[0018] With reference to the accompanying figures, embodiments of
the invention will now be described in greater detail. In FIGS. 1
and 2A-2B, a tether release mechanism 100 is shown. Tether release
mechanism 100 comprises an initiator 105 positioned within a
housing 110. Initiator 105 may be configured such that it is
non-flashing and non-propulsive. In other words, initiator 105 does
not emit a flash and has no loose parts (parts that leave the
device other than a tether or similar released articles--e.g., a
bolt). Initiator 105 is provided with an inherent seal to prevent
the external (external to the initiator) release of pyrotechnic
residues upon deployment. Thus, an o-ring need not be used in order
to seal the initiator in the housing and prevent propulsion and
flashing. This may also be useful because it may allow the device
to be classified in a less restrictive hazard category. As one
having ordinary skill in the art will appreciate, initiator 105 may
be activated pyrotechnically or otherwise.
[0019] Initiator 105 obtains its aforementioned inherent seal by
virtue of having an output cup with a redrawn end. In other words,
the end of initiator 105 is rolled back inside itself, "unrolls",
and extends during deployment, thereby providing the force
necessary to actuate the cutters described herein. Such "redrawn"
initiators have been disclosed and described in greater detail in
copending U.S. patent application Ser. No. 10/729,702 filed Dec. 5,
2003 and titled "Assemblies including extendable, reactive
charge-containing actuator devices." Other embodiments of such
initiators have been disclosed and described in greater detail in
copending U.S. patent application Ser. No. ______ filed on the same
day as the present application and titled "Assemblies including
extendable, reactive charge-containing actuator devices." The
disclosures of these two applications are hereby incorporated by
reference in their entireties.
[0020] Tether release mechanism 100 may be mounted on the back of
an inflator module. Tether 50 in FIG. 1 extends through an opening
115 formed within the housing 110. A cutter 120 having a cutting
blade 121 is operatively connected with the initiator 105. This
allows deployment of initiator 105 to actuate the cutter 120, as
described below.
[0021] Cutter 120 is slidable within a cutter slot 122 formed in
housing 110, as best seen in FIGS. 2A-2B. Cutter 120 is configured
and positioned such that it may be moved from a position adjacent
to opening 115, as shown in FIG. 2A, to a position at which it is
at least partially coincident with opening 115, as shown in FIG.
2B. Once initiator 105 has been deployed, cutter 120 is actuated or
moved axially within housing 110 such that it extends into opening
115, thereby allowing cutting blade 121 to cut through tether 50.
Opening 115 in the embodiment depicted in FIGS. 1 and 2A-2B
comprises a tether restraint structure configured to secure tether
50 until it is released by actuation of cutter 120.
[0022] Cutter 120 may be positioned within cutter slot 122 such
that it is only slidable after a threshold amount of force has been
applied to cutter 120. For example, cutter 120 may be tightly
positioned within cutter slot 122 such that a threshold amount of
friction must be overcome before cutter 120 can be slid up to
opening 115. In this manner, unintentional repositioning of cutter
120 can be prevented or at least minimized. It may be desirable in
some embodiments to configure the device such that a level of force
just under that provided by the initiator is required to move
cutter 120.
[0023] A second embodiment of the invention is shown in FIGS.
3A-3C. Tether release mechanism 200 includes an initiator 205
positioned within a housing 210. Like initiator 105 in the
embodiment shown in the previous figures, initiator 205 is
configured such that it is non-flashing and non-propulsive.
Initiator 205 therefore does not emit a flash and has no loose
parts that it propels upon deployment. Initiator 205 is also
provided with an inherent seal to prevent the external release of
pyrotechnic residues upon deployment.
[0024] Housing 210 again has an opening 215 formed therein and
extending from one side of housing 210 to the other and serving as
a tether restraint structure configured to secure a tether until
the tether is released by actuation of a cutter 220. Cutter 220 in
this embodiment does not comprise a cutting blade. Instead, cutter
220 comprises a piston having an opening 225 formed therein. Piston
220 is positioned in a cylindrical slot 222 within housing 210 and
is configured to be slidable within slot 222. Piston 220 may be
frictionally engaged within the portion of housing 210 which
defines slot 222 such that a threshold level of force is required
to slide piston 220 within slot 222. Piston 220 is configured such
that, prior to deployment of the initiator 205, the opening 215 in
the housing 210 is aligned with the opening 225 in the piston 220,
and wherein, following deployment of the initiator 205, the opening
225 in the piston 220 is moved out of alignment with the opening
215 in the housing 210.
[0025] A tether (not shown) may be strung through the aligned
openings 215 and 225. Upon deployment of initiator 205, the force
on piston 220 causes the misalignment of the two openings. The
shearing force from the sliding of piston 220 within slot 222 may
be used to sever the tether. Of course, many alternatives are
possible. For example, the portion of piston 220 that defines
opening 225 may be sharpened to further facilitate cutting the
tether. A cutting blade may also be provided to cut the tether if
desired. As yet another alternative, in some embodiments it may be
desirable to provide an opening in the housing that is sized
differently on opposing sides of the housing. This may allow for a
tether to be cut on one side of the opening only (the side where
the edge of the opening in the housing and the edge of the opening
in the piston come into contact first). An example of such a
feature can be seen in the embodiment of FIGS. 7A and 7B.
[0026] Still another embodiment of the invention is depicted in
FIGS. 4A-4B. Tether release mechanism 300 again includes an
initiator 305 positioned within a housing 310. Initiator 305 is
non-flashing and non-propulsive such that it does not emit a flash
and has no loose parts that it propels upon deployment. Initiator
305 is also provided with an inherent seal to prevent the external
release of pyrotechnic residues upon deployment.
[0027] Tether release mechanism 300 includes a tether restraint
structure 315. Tether restraint structure 315 in this embodiment
comprises a clip. Clip 315 is configured to snap into a recess 316
formed within the housing 310. Clip 315 has two prongs 317 that may
be somewhat flexible to allow them to bend and snap into place
within recess 316. It should be understood, however, that
embodiments are contemplated which include only a single prong.
Clip 315 is also configured to secure a tether 50. In this
embodiment, tether 50 is looped around an opening at end 318 of
clip 315.
[0028] Clip 315 is configured to secure tether 50 until the tether
50 is released by actuation of a cutter 320. Cutter 320 is
positioned adjacent to initiator 305 so that the deployment force
from initiator 305 can be translated to cutter 320. Cutter 320 is
slidable within slot 322, which is formed within housing 310. Upon
deployment of the initiator 305, cutter 320 is configured to sever
the prongs 317 of clip 315, thereby releasing tether 50, as shown
in FIG. 4B.
[0029] Any of the embodiments described above can be used to
restrain a tether, deploy an initiator that actuates a cutter, and
release the tether by actuating the cutter. The tether may be
restrained by an opening in the housing, as in the embodiments
shown in FIGS. 1-3C, by a clip, as in the embodiment shown in FIGS.
4A-4B, or by any other similar structures that this disclosure
would suggest to, or otherwise available to, a person having
ordinary skill in the art. Each of the foregoing are examples of
restraining means for restraining an airbag tether.
[0030] The tether may be released with a cutting blade, as in the
embodiment shown in FIGS. 1-2B and 4A-4B, by a piston having an
opening formed therein so as to provide a shearing force, or by any
other similar structures that this disclosure would suggest to, or
otherwise available to, a person having ordinary skill in the art.
Each of the foregoing are examples of releasing means for releasing
the tether from the restraining means. The tether may be released
by directly cutting the tether. The tether may alternatively be
released by cutting a tether restraint structure restraining the
tether.
[0031] One embodiment of a "redrawn" initiator for use in
connection with various embodiments of the invention is shown in
FIG. 5. Initiator 400 is configured to provide an inherent seal to
prevent the external release of pyrotechnic residues upon
deployment, as previously described. Initiator 400 includes an
extendable initiator cup 410, a charge 420, and two electrical
connectors 422 and 424.
[0032] Extendable initiator cup 410 is folded in or rolled back
inside itself prior to deployment. Upon deployment of the charge
420, the initiator cup 410 is unrolled or unfolded, at least
partially, to thereby extend the initiator cup 410 (as shown in
phantom in FIG. 5) and provide a force that can be used to actuate
a cutter or other such devices. This force can be provided via
initiator 400 without any flash, spark, or any other external
release of pyrotechnic residues.
[0033] Upon deployment, the reactive charge 420 reacts to produce
reaction products that can extend the extendable initiator cup 410
from a first length to a second length, wherein the second length
is greater than the first length. As will be appreciated by those
skilled in the art, the reactive charge 420 can include one or more
known reactive charge materials, such as a pyrotechnic, which can
be actuated by an electrical current introduced through electrical
connectors 422 and 424. Charge 420 may, for example, include a fuel
slurry and an oxidizer slurry mixed together. Examples of reactive
charges known in the art and useful in the initiator device of the
invention include mixtures including zirconium and potassium
perchlorate (ZPP).
[0034] The extendable initiator cup 410 is desirably sealed around
storage chamber 426 such that the reaction products released from
charge 420 do not escape from the storage chamber 426 and are
therefore available to extend initiator cup 410. This provides
initiator 400 with an inherent seal to prevent the external release
of pyrotechnic residues upon deployment. The extendable initiator
cup 410 may be formed of a lightweight and/or thin material. In one
embodiment of the extendable initiator cup, the cup is formed of a
metal, such as, for example, stainless steel. As will be
appreciated by those skilled in the art, the size, shape,
configuration, and materials used in manufacturing of the
extendable initiator cup can vary depending on the desired
application. Likewise, the amount of reactive charge provided to
extend the extendable initiator cup may depend on, for example, the
type of reactive charge used, the size of the storage chamber, as
well as the stroke, construction, and materials of the extendable
initiator cup. Varying these parameters in accordance with desired
outcomes and configurations will be apparent to one of ordinary
skill in the art upon review of the disclosure provided herein.
[0035] Those having skill in the art will also appreciate that,
whereas the embodiment depicted in FIG. 5 includes an initiator cup
that is folded inside itself, other folds are available and
suitable for use in connection with embodiments of the invention.
For example, other embodiments may be folded in accordion-style on
the sides or may include corrugations. Still other embodiments may
include multiple folds, some of which fold the cup inside itself,
and others of which fold the cup laterally with respect to the
deployment direction, or otherwise. The pressure from the reaction
products, resulting from the initiated reactive charge, may extend
the extendable initiator cup by causing the corrugations and/or
folds to widen, flatten, and/or unfold, at least partially.
[0036] Yet another embodiment of the invention is depicted in FIGS.
6A-7B. Tether release mechanism 500 includes an initiator 505 (see
FIGS. 7A and 7B) positioned within a housing 510. Initiator 505 is
non-flashing and non-propulsive such that it does not emit a flash
and has no loose parts that it propels upon deployment. Initiator
505 is also provided with an inherent seal to prevent the external
release of pyrotechnic residues upon deployment.
[0037] Tether release mechanism 500 also includes a tether
restraint structure 515, which in this embodiment comprises an
opening 515 formed within housing 510. Tether release mechanism 500
further includes a pin structure 519, which in this embodiment
comprises a split spring pin 519. The function of split spring pin
519 will be discussed in greater detail below.
[0038] As shown in the cross-sectional views of FIGS. 7A and 7B,
tether release mechanism also includes a cutter 520, which
comprises a piston having an opening 525 formed therein. Piston 520
is positioned in a cylindrical slot 522 within housing 510 and is
configured to be slidable within slot 522. One end of piston 520 is
positioned adjacent to the redrawn portion of initiator 505
(extendable initiator cup 511) such that the force of unrolling and
extending initiator cup 511 can be transmitted to piston 520.
[0039] Like some embodiments previously discussed, piston 520 is
configured such that, prior to deployment of the initiator 505, the
opening 515 in the housing 510 is aligned with the opening 525 in
the piston 520, and wherein, following deployment of the initiator
505, the opening 525 in the piston 520 is moved out of alignment
with the opening 515 in the housing 510. A tether 50 may therefore
be strung through the aligned openings 515 and 525. Upon deployment
of initiator 505, the force on piston 520 causes the misalignment
of the two openings. The shearing force from the sliding of piston
520 within slot 522 may be used to sever the tether 50.
[0040] Unlike any of the previously disclosed embodiments, tether
release mechanism 500 also includes a vent actuator 530. Vent
actuator 530 is configured to alter the status of a vent opening in
response to the deployment of the initiator 505. In other words,
vent actuator 530 is configured to open and/or close a vent opening
in response to the deployment of initiator 505.
[0041] Vent actuator 530 includes a connecting rod 532. Connecting
rod 532 is attached to piston 520 at the distal end (relative to
initiator 505) of piston 520. Split spring pin 519 prevents piston
520 from exiting the housing 510. Connecting rod 532, on the other
hand, is capable of passing by the split spring pin 519 due to its
smaller diameter such that it can, at least partially, exit the
housing 510. At the end of connecting rod 532 opposite from the end
attached to piston 520 a vent door 535 is connected with the
connecting rod 532. Vent door 535 can be used to selectively block
and/or unblock a vent opening in an inflator housing, an airbag
cushion, or elsewhere.
[0042] For example, as illustrated in FIG. 7A, vent door 535 blocks
vent opening 60 prior to deployment of initiator 505. Following
deployment of the initiator 505, tether 50 is cut and vent door 535
is simultaneously moved away from vent opening 60, as shown in FIG.
7B, thereby allowing inflation gas to enter or exit vent opening
60, depending on the location of the vent opening 60 and other
characteristics of the corresponding airbag module. Of course,
other embodiments are contemplated in which a vent door or other
structure operatively connected with an initiator closes a vent
opening in response to deployment of the initiator.
[0043] Without further elaboration, it is believed that one skilled
in the art can use the preceding description to utilize the
invention to its fullest extent. The examples and embodiments
disclosed herein are to be construed as merely illustrative and not
a limitation of the scope of the present invention in any way. It
will be apparent to those having skill in the art that changes may
be made to the details of the above-described embodiments without
departing from the underlying principles of the invention. In other
words, various modifications and improvements of the embodiments
specifically disclosed in the description above are within the
scope of the appended claims. The scope of the invention is
therefore defined by the following claims. Note also that elements
recited in means-plus-function format are intended to be construed
in accordance with 35 U.S.C. .sctn. 112 6.
* * * * *